Eta to affect southwest Florida this weekend (H. Michael Mogil, CCM, CBM, NWA-DS*)
Tropical Depression Eta (Fig. 1) is almost back to tropical storm strength; the latest 3 a.m. CST advisory (Friday) places peak sustained winds at 35 miles per hour. As Eta, currently moving slowly northward, starts moving northeastward during the next few hours, the storm will traverse warm ocean waters and further distance itself from debilitating land influences. Intensification is expected.
By Sunday afternoon, an upper-level low-pressure system, currently over the East Texas – western Louisiana area, will have moved southeastward and established itself to the southwest of our area. Current thinking from the National Hurricane Center suggests that this upper low will interact with Eta, allowing the storm to take a northerly or northwesterly path once it has moved across Cuba into the Florida Straits. If this path materializes, southwest Florida will be very close to the center of a strong tropical storm by Sunday night and Monday (Fig. 2).
This brings a potential potpourri of weather, hydrologic, and oceanic threats to southwest Florida. In addition to high winds (and the ever-present spotty to widespread power outages), widespread heavy rainfall (of at least two to four inches) can be expected. This can lead to localized highway and drainage flooding.
Along the southwest Florida coast, wave action can lead to rip currents and some beach erosion; Also, water levels will rise as the storm approaches (but not as high as they could because Sunday is midway between full and new moon phases – https://www.tide-forecast.com/locations/Naples-Florida/tides/latest).
It is still too early for the National Hurricane Center to post any tropical storm watches or warnings for our area. It is also too early for any other watches or warnings (for example, flooding). However, based on the current track and expected intensification, local forecasts are showing tropical storm force wind conditions for Naples and nearby areas late Sunday night into Monday.
Meanwhile, a Flood Watch will go into effect for Friday night through Tuesday evening for eastern Miami-Dade, Broward, and Palm Beach Counties. For these areas upwards of seven inches of rainfall is anticipated.
Weak upper steering currents will set up once this scenario unfolds, and south Florida will remain in the broad circulation pattern of Eta as the system moves slowly northwestward early next week. This will allow high tropical moisture values to remain across our region. With less cloudiness (and more solar heating), a scattered to widespread shower and thunderstorm pattern will be established. These storms will add to any rainfall deposited by Eta.
Eta’s projected path has shown lots of fluctuations during the past 24 hours. Given the expected weak upper-level steering currents, look for more changes in path and intensity forecasts during the next few days.
Please keep updated on the storm’s evolution, movement, and expected impacts.
© 2020 H. Michael Mogil
Originally posted 11/6/20
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